We're going to turn to details on the deadly shooting rampage in Las Vegas. Surveillance video shows the final standoff between police and the couple that killed three people, including two officers in an M bash. Pierre Thomas is tracking the story. Reporter: You're looking at the final fatal moments of two alleged killers. Jared and Amanda miller, holed up at a Walmart in Las Vegas. There they are in the auto section, caught on surveillance tape, as police secretly monitor them. Amanda is wounded. And it appears the couple is contemplating suicide. He points his gun at her. She points her gun at him. Looks like they're shooting at each other. She just shot him. Reporter: On Wednesday, authorities corrected the record. In fact, just prior to this video, we see where the male was shot by police gunfire. Reporter: So, police say they killed Jared. And his wife took her own life. This all came after the millers had allegedly killed two police officers in a pizzary Ya. Draping a one, a swastika and the revolution has begun. How you go from an action to murdering police officers, is something we all need to figure out as quickly as we possible can. Reporter: But could the tragedy have been prevented? Neighbors say the couple had discussed killing police. And authorities say the millers had three encounters with police, including one about threats to a state motor vehicle's office. But no hint of violence. And this morning, there's growing concern about domestic terrorism. The attack came only 72 hours after a self-styled sovereign citizen attacked the white house in Georgia, spewing anti-government rhetoric. Homeland security and FBI officials are deeply concerned. And have prepared a bulletin warning police to be on the lookout for anti-government violence.

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